Ya, I agree with the others. I will hold a spot for people if I like them and want them in care and I charge them $200/month and it goes towards nothing. I also charge a reg. fee of another $200 and this goes towards their last month of care. So, upfront, they have to pay me $400. Always always have a contract! It sets a precedence/tone for your business and it lays out what is expected from both you and the parents...no confusion!
I also agree with Judy, this is a business and in business you are out to make money. Otherwise, why would you bother. Do charity work instead. I'm not a charity and I do this for the money, it's no secret.